Fractal analysis of catalyst surface morphologies on hydrogenation in process of 2-((1-benzylpiperidin-4-yl)methyl)-5,6-dimethoxy-2,3-dihydroinden-1-one hydrochloride synthesis

Catalytic hydrogenation of 2-((1-benzyl-1,2,3,6-tetrahydropyridin-4-yl)methylene)-5,6-dimethoxy-2,3-dihydroinden-1-one hydrochloride (1) to 2-((1-benzylpiperidin-4-yl)methyl)-5,6-dimethoxy-2,3-dihydroinden-1-one hydrochloride (2) was investigated in batch-slurry reactor. The 5% Pt/C catalysts were chosen for optimizing the catalytic activity. The catalyst activity has been changed by using the differently morphologically structured fractal catalysts. The kinetic terms of hydrogenation for (1) change with the fractal dimensions of the 5% Pt/C catalyst. The most active and selective (with the highest reaction rate for production of (2), and with the least impurities level) is the catalyst K3, and the worst the catalyst K4. This most active and selective catalyst has an intermediate fractal surface dimension, DF,ads = 2.77, and the worst catalyst is represented by almost smooth surface with a high DF,ads = 2.82. The interface D[BW] fractal indices (derived from the thresholded SEM images, at the magnifications in the range 600–2000×) are largest ones for the most suitable catalyst K3, and lowest for the catalyst K4.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (259 K)Download as PowerPoint slideHighlights► The fractal dimensions for the Pt/C catalysts effect the reaction kinetic terms. ► The catalyst “interface” fractal indices are related to the Weibull equation terms. ► The catalyst “interface” fractal indices effect the impurity rate constants.